Have owned 2 99s and 1 98 which are effectively the same car. Obviously I love my Rivieras That said, they all have had supercharger coupler failures, leveling system failures, and trunk leaks, all of which are relatively easy to repair with the leveling system the most expensive to repair. One had a bad intake manifold gasket that leaked antifreeze into the intake that I never repaired. Have problems with the transmission shifting that was fixed by replacing the fluid & filter and then driving it for a couple months. Replaced 1 radiator, 1 oil pressure sending unit for Misc other problems & issues but have been driving these cars for almost 15 years. My current Riviera is a Silver Arrow.